Chlorinated maleic anhydride adducts



Patented July 23, 1946 CHLORINATED MALEIC ANHYDRIDE" ADDUCTS Henry N. Stephens, Gilbert B. Gehrenbeck, and

Donald R. Guthrie, White Bear Lake, Minn., assignors to Minnesota Mining & Manufacturing Company, St. Paul, Minn., a corporation of Delaware No Drawing. Application September 25, 1940, Serial No. 358,368

Claims.

is a soluble and infusible synthetic resin. A salient aspect of this invention concerns resinous products which are adapted to be-dissolved in certain organic solvents for various uses, and which will not liquify when heated.

The resinous product herein described may generally be characterized as a non-fusible resinous material which is soluble in certain organic solvents, e. g. acetone, butyl acetate, etc., and when so dissolved or suitably thinned provides coatin compositions and/or cements having special properties. The cements, for example, may be used to advantage in adhering leather to metal, coated or treated paper to metal, and for other difiicult adhesion problems. Whereas many solvent type rubber cements provide good adhesion to metal, they do not provide good adhesion with leather over long periods of time, perhaps because of oils in the leather. On the other hand, whereas hide glue quite readily adheres to leather, its adhesion to metal is quite poor. Cements as herein defined have the virtue of adhering well to both metal and leather, as well as to a number of other materials. The base of such a cement is a suitable synthetic resinous material, e. g. as above referred to.

We shall first describe a preferred resinous material for our purposes which is, itself, believed by us to possess important patentable novelty.

A preferred resinous material contemplated by us is a type of alkyd resin. More particularly it comes within the general class of alkyd resins made by first producin an adduct of an acid or anhydride such as maleic acid with a conjugate double bond compound such as Chinawood oil, or China-wood oil acid, and then esterifying the resulting adduct with a dihydric or polyhydric material such as glycerine or ethylene glycol, and/or a polyamino compound such as diethylene triamine. We are particularly concerned with resins coming within this general class which have the combined characteristics of being both non-fusible and at the same time soluble in or' ganic solvent such as acetone, butyl acetate, and the like.

Others have prepared esters of adducts, but not of the type or character herein described, to the best of our knowledge. For example, British Patent No. 407,957 (1934) ofMorrell, Marks and Samuels describes the production of a so-called adduct; that is, thisBritish patent describes reacting together China-wood oil and maleic an- 2. hydride to produce the adduct thereof. The resulting material is suggested for use as a varnish or enamel, which may be set up by baking or may be dried by use of cobalt or manganese driers. This British patent also describes increasing the viscosity of such varnish-like adducts by a certain degree of esterification thereof with a dihydric or trihydric alcohol, and suggests certain methods therefor. The degree of esterification of the product of this British patent, produced by heating the adduct with the polyhydric alcohol, is only suflicient to increase the viscosity of the glycerine-adduct mixture to make it more suitable for certain varnish uses: see page 4, end of column 2, of the British patent. The esterlfied product is a "fusible resinous material, 1. e. it becomes less viscouswhen heated and will melt, i. e.,will liquify, if heated up to the temperature to which it was heated in making the same. The

British patent .is really concerned with the making of a liquid or balsam,.as distinguished from a gelled resin.

On this general subject, as background of the prior art, reference is also made to the Chemistry of Synthetic Resins by Carleton Ellis, 1935 edition, volume 2, chapter 40 entitled: The diene synthesis. In this chapter, particularly at page that two possibilities exist in the production of l 858, a description is given of the production of an adduct of eleostearic acid (i. e. China-wood oil acid) and maleic anhydride; this is an example of the diene synthesis. Since eleostearlc acid has three sets of double bonds in its molecular'structure so situate that either two of the three sets of double bonds may be considered a conjugate double bond system, it will be evident the adduct. That is, the adduct wil1 differ somewhat depending upon whether the maleic anhydride joins into the eleostearic acid molecule with one set of conjugate double bonds or with the other. To distinguish between these two adducts, the book by Ellis, at page 858, refers to the alphaeleostearic acid-maleic anhydride adduct and the beta-eleostearic acid-maleic anhydride adduct. As before indicated no novelty is claimed in making this particular adduct or in making an esterification product thereof. We produce a difierent adduct and, therefrom, arrive at a synthetic resin havinga novel and particularly useful combination of properties.

Reference is also made to Patent No. 2,146,671 of Carleton Ellis as prior art. It will be seen that the patentee wasconcerned with the production of a soluble glyceride of an adduct such as tung-maleic adduct, but secured the same by I stopping his esterification or condensation so that i he still had a fusible semi-solid resinous mass: see

page 1, column 1, line 42 of the Ellis patent. If

1 Ellis particular reactants were reacted 'or con-' densed far enough to produce a non-fusible resin,

the resulting materia1 would not have been solcarried beyond the fusible stage, i. e. into the infusible stage, but yet is soluble in acetone,

butyl acetate and the like. Illustrative methods of accomplishing this objective are given hereinbelow.

Another object of this invention is to provide a resinous material which can be applied as a coating, for example to metal surfaces, in the production of various articles, e. g. refrigerator boxes, and will set to form a non-fusible hard, tough coating merely upon the evaporation of solvent and exposure to air at room temperatures or higher.

Another object is to produce a solvent type synthetic resinous cement having new and advantageous characteristics.

A further object is to produce composite articles, .for'example chairs or the like, comprising metal covered with leather, the leather being joined Example I [60 lbs. tung (China-wood) 011 and 20 lbs. of.

maleicjanhydride are heated to about 70 to 80 C.,' whereupon a strong exothermic reaction sets in which, with continued stirring, raises the ternperature 40 or 50 (3.; that is, brings the temperature up to 120 C. or of that order. Additional heat is supplied during and/or following this strong exothermic reaction to bring the final temperature of the mass up to about 160 C. to insure completion of the reaction. -An ordinary open enamel kettle may be used as a container for the mass and may be heated with a gas flame or by any other suitable means.

*The whole massisthen cooled to about 80 C., and then is chlorinated. The desired chlorination reaction is efiected by first adding to the mass a catalyst (which is advantageous but not essential) consisting of 36 grams of iodine dissolved in 360 c. c. of ethyl alcohol. Gaseous chlorine is then introduced into the mass, as by use of a perforated glass tube immersed in the mass. During the introduction of the chlorine the mass is constantly stirred as with a glass or enamel coveredmechanically driven stirrer, and the introduction of chlorine is continued until about lbs. of gaseous chlorine have been takenup by the mixture. The chlorine is preferably introducedso that it is dispersed uniformly throughout the massin small bubbles, in order to intimately contact all portions of the mass. chlorination is an exothermic reaction but the rate of reaction decreases as the chlorination continues, with a consequent decrease in the evolution of heat. While the evolution of heat is sufilcient near the beginning of the reaction to maintain the temperature at'around 80 0., toward the end of -the reaction some heat ordinarily The' should be supplied to prevent the temperature from dropping off. 80 C. is not critical for this reaction. Lower temperatures such as 70 C. or

60. C. can be employed. However the mass has a more favorable viscosity for chlorination at the higher temperature of 80 C. and also the reaction proceeds at a more feasible rate. However if the temperature of the batch is allowed to rise much above 80 C., the color of the finished product becomes very dark and a great deal of HCl is given off. The product seems better when made at a temperature of the order of 80 C. or at lower temperatures."It will be understood that an entirely satisfactory product can be made at temperatures of the order of C. or lower, the

problem being to provide a suitable rate of reaction and suitable contact between the gaseous chlorine and the adduct mass, and further to maintain the viscosity of the batch low enough so that mechanical mixing can be carried out.

It will be noted that when 10 lbs. of gaseous chlorine are taken up by the adduct mass, the chlorine will be present to the extent of about 12 percent of the weight of the unchlorinated adduct. Higher or lower percentages of chlorine may be used, e. g. from 5 to 15 or 20 percent, but ordinarily adducts in which the chlorine is present from 10 to 14 or 15 percent of the unchlorinated adduct are preferred. H

1000 grams of the chlorinated adduct, made as just described, were placed in an enamel kettle with 139.5 grams of glycerine. The mass was heated gradually to C. Gases or vapors were given off as the temperature rose and this tended to cause foaming. It will be appreciated that one of the byproducts of an esterification employed for minimizing the foaming difiiculty is to bubble'a suitable gaseous material through the mass while it is being heated. Sulphur dioxide works well for this purpose. When the mass has been brought up to 160 C., or of that order, it is maintained at this temperature, with constant stirring, until the esterification reaction has proceeded far enough so that the mass gels. This point of gelation is-very marked in a reaction of this kind. While it is true "that, before gelation, the mass gradually increases in viscosity with continued heating, the point of gelation represents a very'marked change and occurs quite suddenly. Prior to gelation, when a glass rod is lifted out of the mass, the material which clings The resulting glycerme-adduct resinous ester,

after being reacted to the stage just described (and after cooling), can be employed for various purposes. One important use is in the making of cements. The ester canbe dissolved in acetone to the extent of three parts of ester to seven parts of acetone, and the resulting cement can'be employed for a number of unique uses. For example it can be employed to join leather to iron, nickel or other metal surfaces.

The resinous glycerine-adduct ester just described has the unique property of being, at one and the-same'timasoluble in various materials" such as acetone, butyl acetate and the like, and I at the same timebeing an infusible type of resin.

In the above example instead ofem-ploying tung or- Chinawood oil, other-oils, particularly those which-have. at least'one conjugate double bond system, orelse inwhich a-conjugate double bond resulting product. is. asolid gel which it is difficul't to chlorinate for mechanicalreasons, 1.. e. because of the-difficultyof securing, intimate contact be.- tween the solid adduct andthe. gaseouschlorine. Of course a liquid or solidreagent can be employed under such circumstances, ifdesired, tominimize themechanical difficulty. The corresponding. oiticicaoil resinous ester is somewhat. softer than that produced. with ordinary raw tung oil. There is some slightdifference between theresin produced in employing alpha and beta .eleostearin; however, this difference is not nearlyas markedas the difference between the resin .produced with .tung oil (i. e. alpha .eleostearin) andthat produced with oiticica oil.

.Inplace of chlorine, we have also successfully employed other reagents to secure our resins having the special property of .being soluble in acetone and, the like, while at, the same time being of the infusible type. Among these other reagents are stannic chloride, sulfuryl, chloride, hydrogen chloride and sulphur. Chlorine is illustrative of thehalogens; bromine may. also be used.

Stannic chloride will react with the adduct, and the .glyceride or ester producedwith such an adduct will be a tough resin. The stannic chloride possesses an advantage in certain situations in that it may be added as a solid (where reaction with gaseous chlorine may be diificult mechanically). However, stannic chloride is relatively expensive compared with chlorine and also leaves a water-soluble salt, i. e. stannous chloride, in the reaotionproduct which is sometimes undesirable, as from a corrosion point of view.

Sulfuryl chloride reacts with the adduct, adding about 40 percent. of its chlorine; however, the amount of chlorine added varies with the conditions of thereaction. This reagent can be added as a liquid at room temperatures and under some special circumstances is more desirable for this reason than gaseous chlorine. The final glyceride-adduct resins produced by this route are apparently equal in quality with those made with an equal amount of chlorine added as a gas. Addition of the chlorine by this reagent is more expensive as will be obvious.

'Where hydrogen chloride is reacted With the adduct, the final glyceride-adduct resins produced are soluble in acetone and the like but are somewhat softer than those produced according to Example I hereof, i. e. reacting chlorinexgas with the adduct.

Sulphur will react with the adduct on heating to esterification temperatures or of that order, e. g. at temperatures of the order of 160 C. This has the advantage that the freshly formed adduct need not be cooled down before reacting with the sulphur. It also has the further advantage that the reaction with sulphur can continue, or even take place simultaneously with a portion of the esterification. Withincreasingamounts of sulphur (.e. g. over that shown in Example II, hereinafter), solubility is further increased but the resin becomes darker in color, of less satisfactory and .triethylene glycol.

odor and proceeds toward the brittlestage. .1-'3.% e. g. 2% or so of sulphur, based'onthe. adduct, reacts quite completely. Substantially higher percentages, e. g. above 3% or so, tend to. leave insoluble, dark, flock-like material in thei'adduct, the presence of which it is desired to. mini.- mize for the sake of appearance.

An oxidized product, prepared byv blowing air through the heatedadduct beforeesterifylng, was readily soluble in acetone, butyl acetate and the like, but was dark colored, soft and sticky. Accordingly, this resin would not be as satisfactory for use as a cement as one prepared as described in Example I hereof.

I In the .esterification of the acid adduct, various alcohols and amines have been used. Of those esterifying agents tried, glycerine, appears to produce the toughest. resins. The amountof glycerine employed is normally calculated. on the basis of the freeacid groups (or anhydride groups figured as equivalent carboxyl groups) of the maleic anhydride or equivalent; however, the resin is ordinarily set up to the gel stage before the reaction is entirely completed. Considerable variation inratios of glycerine to free acidgroups can be employed while still producing a good resin ester.

In place of. glycerine, other polyhydric, com pounds which may be employed include ethylene glycol, and other glycols, such as diethylene glycol Still other polyhydric compounds which may be employed under suitable conditions include sor bitol, mannitol, etc. Of the amines which may be used for this purpose, di-,

ethylene triamine .is illustrative. Aniline and like monoamines and monohydroxy, compounds such as butyl alcohol can be used to replace part of the glycerine or equivalent, with a. correspondingv softeningof the. final resin, butit is necessary that the glycerine or the like predominates over any monoamineor monohydroxy. compound employed in order to produce an infusible resin.

In place of maleic anhydride, otherv chemically similar materials may be employed in. which a group is preferably activated by a carboxylgroup, although, where desired. it may be additionally activated by one or more other groups, such as carbonyl, cyanide and aldehyde groups, as well as by an additional ethylene group.

The .resin of Example I and equivalent resins have excellent adhesion to almost any dry surface, and are so tough and adherent when cooled that they are very difficult to handlein this manner. Therefore,,when it is desired tomake a solvent type. adhesive cement we prefer to dump the resin .directly from the kettle; in which it is made into a mixer containing a sufiicient excess of either fresh solvent or dilute resin solution so that the mean temperature of the final mixture is below the boiling point of the solvent. Acetone has been used as a solvent with satisfaction. Methyl ethyl ketone, butyl acetate, and, other solvents have also been used.

Whereas, hereinabove we have discussed the chlorination or other treatment of the adductwin undiluted state, we also contemplate the ,use of a more or less inert solventfor the adduct. x-Where dissolved in a solvent, for example, carbon tetrachloride, or other solvent depending upon the exact nature of the adduct and the inertness of the solvent toward chlorine; the viscosity oI the' employed.)

, even at room temperatures or below. By employing .a suitable solvent an adduct produced from dehydrated castor oil oanlikewise be satisfactorily used in making the resinous ester. Sometimes the adduct is made in the. solvent, in which case there may already be sufiicientsolvent present to serve the purpose just described.

Additional methods and reactants for making our soluble and infusible ,resins will now be,

described, 1

1 Example]! 100 grams oiticica oil and 26.5 grams of maleic anhydride are heated to 150 C., with stirring. The reaction is normally complete when this temperature is reached; in fact, the reaction is approximately completed at about 120 C. Yellow color is produced in the mass during the early stages of the reactionand the disappearance of this color indicates completion of the reaction. (This is equally true where tung oil is Then, while the temperature of the mass is at approximately 150"? C., 16.5 grams of glycerine and 3 grams of sulphur. are added, at the same time, and the mass is heated, within the range of 160 to 180 C., until the resulting resinous ester gels. This point or stage ofreaction will be readily evident, as was pointed outmore in detail in connection with Example 1 hereof, The gel produced is normally of a dark brown color in this example. softer than a similar gel made with tung oil.

Example III I 81grams of tung oil and 19 grams of maleic anhydride were heated to 160 C.,,with stirring, to complete the reactionin, the forming of the adduct. The mass was then cooled to room temperature and 5 grams of stannic chloride pentahydrate were added as a powder, withstirring. This mass "was heated slowly to 160 C., and held at such temperature until'bubbling (caused by escape of the water of hydration of the stannic chloride) ceased. Then, to this mass at 160 C.,

11.8 grams of glycerine were added and the tem-v perature maintained at or about 160 C., until the formation of a gel as hereinbefore described. The resulting resin was of infusible nature and soluble in various solvents, e. g. methyl ethyl ketone, acetone, butyl acetate, etc. 7 l

Eatample 1V 2 81 grs. of tung oil, 19 grs. of -maleic anhydride were heated to 160 C., with stirring, as above described. The resulting adduct was then cooled to about 80 C. and gaseous'fchlorine bubbled therethrough until the weight of the adduct increased by approximately 5 percent; that is, about 5 grams of chlorine were. added to and combined with the adduct. Then 11.9 grams of glycerine were added and the mass was heated to a temperature within the range-of 180 to 200 C., with stirring, and the mass was maintained at this temperature until it set up a gel, as hereinabove described; 1

The resulting resin was not as soluble as res-.- ins with higher chlorine content, but could be dissolved to a rather gelatinous type of solution in various solvents such as methyl ethylketone and acetone, while being an infusibletypeof resin.

90 grs. of chlorinated adduct produced as in Example IV, were introduced into a glass beaker and to this was added 7.7 grs. of glycerine and The resulting resin is 7.7 grs. of aniline, both at the same time. ,The mass was heated, with stirring, to, a'temperature of 180 to 200 C. and produced a somewhat softer resin than that of Example IV, though the resin was infusible. The resinous ester was also. more readily soluble in solvents such as methyl ethyl ketone, acetone, and the like.

The soluble and infusible adduct-glyceride resins of our invention have a number of uses hereinabove adverted to. When dissolved in solvents such as acetone or the like, for example to the extent of percent solids, they adhere extremely well to both metal and leather, which makes it possible to make composite articles of high qual-r, ity in which leather is adhered directly to metal. Whereas animal glue adheres quite well'to leather, its adhesion to metal is very poor. On the other hand, whereas certain rubber cements of the solvent type adhere well to metal, they are not satisfactory adhesives for leather. Apparentlythe oils in the leather soften or attack the rubber cement and accordingly, over a period of time weaken it as an adhesive for leather. The

- cements asdefined in the present application ,(consisting of little glass spheres coated on'drying oil treated, resin treated or other treated paper) to a metal or painted metal panel or to wood, for attaching leather to metal in autobody construction, etc.

It will be understood that use as an adhesive cement is only one of many uses for our new type of resins, i. e. soluble and infusible synthetic resins. As distinguished from use as an adhesive cement (which involves holding two surfaces to-' gether), our synthetic resins may be employed to advantage 'as a coating compositionffor ex: ample as a priming coat in the enameling of metal surfaces, in which case they .would ordi narily'be used with enough solvent to give them the. desired consistency. Also they maybe used as a, finishing coat or enamel for metalor other surfaces. Where used as an enamel, suitable pig-1 ments (e. g. red iron oxide, etc.) and suitable fillers (e. g. talc etc.) are commonly adde'd'there-i to, the nature of which are well understoodin the enamel art. Our, synthetic resinshave good elastic properties at ordinary room temperatures and also good adhesion toawide variety of materials. In addition to adhering well to the materials above mentioned, they also adhere well to rubber, glass, wood, paper and other' cellulosic materials, natural resins or varnish films, other synthetic resins such asphenol aldehyde resins, etc. I

The use of our chlorine reacted adducts or equivalent in making our resins, as distinguishedv from using ordinary maleic anhydrideChinawood oil adducts, brings about the following advantages, amoug others: 1

(1) The resulting resin ester,- condensed to the stage of infusibility, is soluble, e. g. in acetone and the like. r

The f i -ad ive 9 t ssinisi 'i High quality chairs and other creased. (The specific adhesion of resins does not. necessarily correspond with, or change in line with, their efiective adhesion.)

(3) The tendency of the resin to oxidize is reduced, which reduces or eliminates the susceptibility of the resin to shrivelling in film form.

It is of course true that, employing normal types of adducts heretofore available, where the reaction of the same with glycerine was stopped before the ester gelled, as in the Ellis patent, supra, the resulting ester was soluble in various solvents such as acetone, toluol and the like. However, such an ester is not an infusible resin; that is, upon heating to a temperature of the order of that at which it was originally produced, such a resinous material will become liquid and free flowing.

However our resins, as hereinabove described, will not lose their gel-like properties upon heating, and they will not liquify, nor flow freely under the force of gravity, when reheated to the. temperature at which they were originally produced, nor when heated to any temperature.

Where herein or in the appended claims we employ the term "non-fusible or "infusible in defining our resins we, of course, do not thereby exclude resins which will soften somewhat when heated within certain temperature ranges but we do exclude resins which will melt upon heating, i. e. will form a liquid upon heating or will freely flow upon heating.

Comparing the glyceride of our chlorinated adduct with an otherwise comparable glyceride of an unchlorinated adduct, both carried to the same degree of esterification orgelation, i. e. to the same approximate degree of molecular aggregation (same molecular weight except for chlorine), the temperature range for a given plasticity is higher for the chlorinatedresinous ester than for the unchlorinated ester. The significance of this will be illustrated by the fact that, when the chlorinated resin is used for example as a cement, the resulting cement bond will be more heat-resistant than where the un'chlorinated resinous ester is employed.

Other interesting variations in the resulting resin may be accomplished by hydrogenation or partial hydrogenation of the adduct, usually prior to esterification.

Important physical properties of our synthetic resins may be controlled within limits by controlling the conditions of producing the same and may be further controlled or varied by the addition, in suitable proportions, of various ingredients such as ethyl cellulose, chlorinated rubber (Parlon, made by the Hercules Powder Company), nitrocellulose, various vinyl resins such as vinyl butyrals, etc. Wide percentage range variations of these ingredients are contemplated.

It will be understood that the illustrative methods herein described for producing soluble-and infusible synthetic resins have broad application, especially in relation to solvent type cements, whether the same comprise the particular soluble and infusible synthetic resins herein illustrated or others having similar or comparable properties.

'Whereas hereinabove iodine dissolved in alcohol is given as an illustrative catalyst in producinga chlorinated adduct, other catalysts such as ferric chloride or certain other amphoteric metals or metals of changeable valence, or their chlorides, or still other suitable catalysts may be used but are not essential.

It will be noted from the above (in reference to leather) that our resins are resistant to attack by or solution in oils such as drying or nondrying oils or like glycerol esters. Also it is important that our resins are resistant to attack by, and do not dissolve in, petroleum hydrocarbons, such as gasoline, kerosene and the like. In this connection our resins have use in impregnating or treating gaskets and other porous materials, including tubing and the like, which must resist contact by oils and petroleum fractions.

Also it is to be understood that the teaching of the prior art on accentuating waterproofness of alkyd resins as a whole is also, in general, applicable in the case of our resins.

The above description is illustrative and not limiting and we comprehend all embodiments within the scope of the appended claims.

What we claim is:

1. An acetone-soluble resinous glyceride of achlorinated maleicanhydride-China-wood 011 adduct, which said resinous glyceride will not form a liquid upon heating.

2. As a new product, an adduct of maleic anhydride and China-wood oil reacted with chlorine,

so that the chlorine is present to the extent of 5-15 percent by weight of the adduct.

3. In the preparation of a soluble and infusible synthetic resinous condensation product, the step whichcomprises interacting chlorine with the adduct of maleic anhydride and eleostearin at a superatmospheric temperature not greater than approximately C. i

4. As anew product, an adduct of maleic anhydride and a fatty oil having a conjugate double bond molecular structure, said adduct being reacted with chlorine so that the chlorine is present to the extent of 5-15 percent by weight of the adduct.

5. A synthetic resinous polyhydric alcoholester of a chlorinated adduct of maleic anhydride and:

a fatty oil having a conjugate double bond molecular structure, which said resinous ester will not form a liquid upon heating, and is soluble in acetone.

HENRY N. STEPHENS. GILBERT B. GEHRENBECK. DONALD R. GUTHRIE. 

